voice "auto" and OpenAI preset names now follow the key's voice settings

Status: available. A request that named any voice - including “auto” or an OpenAI preset like “alloy” - silently switched off the key’s pinned voice and gender settings, and a preset then landed on each vendor’s house default, so the voice could change identity or gender when routing failed over. “auto” now always defers to the key, and a preset defers to the key whenever the key has voice settings.